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Subject: Re: [hwloc-users] Problems on SMP with 48 cores
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2012-03-13 14:10:18


Le 13/03/2012 18:57, Samuel Thibault a écrit :
> Brice Goglin, le Tue 13 Mar 2012 18:55:29 +0100, a écrit :
>> Le 13/03/2012 17:04, Hartmut Kaiser a écrit :
>>>>> But the problems I was seeing were not MSVC specific. It's a
>>>>> proliferation of arcane (non-POSIX) function use (like strcasecmp,
>>>>> etc.) missing use of HAVE_UNISTD_H, HAVE_STRINGS_H to wrap
>>>>> non-standard headers, unsafe mixing of
>>>>> int32<->int64 data types, reliance on int (and other types) having a
>>>>> certain bit-size, totally unsafe shift operations, wide use of
>>>>> (non-C-standard) gcc extensions, etc. Should I go on?
>>> More investigation shows that the code currently assumes group (and
>>> processor) masks to be 32 bit, which is not true on 64 bit systems. For
>>> instance this (topology-windows.c: line 643):
>>>
>>> hwloc_bitmap_from_ith_ulong(obj->cpuset, GroupMask[i].Group,
>>> GroupMask[i].Mask);
>> Try applying something like the patch below. Totally untested obviously,
>> but we'll see if that starts improving lstopo.
> That won't work on 32bit systems, where the mask is 32bit only

Of course. I am just trying to see if we can get something working
better on 64bits or if there are other problems.

Brice